| Abstract/Description or Keywords |
The objective of this project was to upgrade reconnaissance terrain stability maps to detailed terrain stability maps at terrain survey intensity level (TSIL) C for Spruce Creek, located near D'Arcy. This work was carried out under the auspices of the Small Business program, Squamish Forest District. These maps will be used in planning forestry activities and for community watershed management. Mapping methodology is discussed in more detail below.----- Management implications and recommendations based on ratings for slope stability, erosion potential and sediment delivery are listed in Tables 4, 5, and 6. Although much of the upper Spruce Creek area is mapped as unstable and potentially unstable, much of this terrain is inoperable, consisting of steep rock and colluvium, large gullies and avalanche tracks. The most significant unstable areas are the steep scarps of the glaciofluvial terraces beside Spruce and Haylmore Creeks. These slopes are being undercut by the creeks, leading to slides. Roads are often built on the relatively flat terrace surfaces above these scarps. Diversion of natural surface and shallow subsurface runoff by a road could lead to destabilization or erosion of the scarp, and the addition of sediment to the creek. Therefore it is important to control the release of water from ditches and road runoff, especially where the road is close to the upper edge of a scarp. terrain stability, erosion, landslide, sediment |
